camera pistol grip tip

This is what I have found useful and I will say why. Using a Nikon D800 and a large lens such as the AF-s 80-400mm lens but would also work with Canon or any make using a large lens with a collar.
Convention say when shooting one should have good stance- arms close to the side and support the camera with one hand and the lens with the other hand gripped around the lens bottom to keep a hands free shot steady.

That may well have been true in the past BUT I find that by fixing the pistol grip to the lens collar and revolving the collar to a more comfortable position one can hold the lens far steadier than ever before, almost eliminating the need for vibration reduction to be used. For the cost of the pistrol grip anyway surely its worth a punt.
I find that having the grip at about half way between pointing down and at right angles fixed on the collar really does help steady a camera down not only from horizontal but vertical camera shake. Great when using autofocus